This project will specify and estimate econometric models of transitions from private, long-term disability (LTD) benefits to Social Security Disability insurance (SSDI) benefits by employees who are on LTD as a result of a mental disorder. Using data from individual LTD claims, the probability of transitioning to SSDI benefits will be modeled as function of: 1) individual employee, employer, and disability characteristics; 2) LTD policy provisions; 3) mental health coverage provided by the employer; 4) availability of mental health treatment resources; 5) employers' disability management efforts; and 6) interstate differences in availability of SSDI and other compensation programs. Data on SSDI costs will also be aggregated over individual claims to the employer-year level for estimating models of SSDI costs per employee (covered by LTD insurance) per year. Data for the project will pertain to approximately 1,400 employers and their 500,00 employees covered by LTD insurance. Administrative data, claims data, data from public sources, and survey data on 278 of these 1,400 employers will be analyzed. Econometric methods will include hazard (duration) regressions as well as multiple hazard models (where return to work and transition to SSDI benefits are the competing risks). Estimation of employer-level costs will use the methods for modeling health expenditures recently proposed by Manning and Mullahy. Several approaches for estimation with missing data will also be tested as strategies for combining our employer survey data with information for all 1,400 employers in the study. The empirical estimates obtained in the study will provide information on the possible implications of changes in mental health benefits and changes in benefit and compensation programs for the continuing rapid rise in SSDI costs for beneficiaries with mental disorders. Estimates will be derived of the impacts, on SSDI receipt and costs, or increased managed care/carve-out coverage, of increased geographic availability of mental health specialty care, and of employers' disability management efforts.